The present invention relates generally to electric motors for automobile applications and, more particularly, to locating electronic components of the motor in places which improve cooling of the electronic components.
U.S. Pat. No. 5,119,466 uses pulse width modulation to control the speed of a permanent magnet dc motor. A speed control circuit is carried by a circuit board disposed within the motor. The circuit board includes a motor control signal converter which receives a motor control signal from a vehicle electronic control unit (ECU) and sends a pulse width modulated signal to a field effect transistor (FET), which is also mounted on the circuit board and joined to a projection of the case of the motor. However, the requirement of the circuit board having a signal converter and FET mounted thereon increases the motor cost. Furthermore, the dissipation of heat created by the FET can be improved.
Another known arrangement provides a FET in a separate housing for modulating power to the motor based on a PWM signal from the ECU. However, this arrangement introduces another component mounted in an already crowded engine compartment.
Accordingly, there is a need to provide an engine cooling motor that includes electronics located in such a manner to enhance heat rejection of the electronic components and to isolate the electronic components from heat generated by the motor coil and bearings.
An object of the invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is achieved by providing a cooling module which includes an electric motor for driving a fan. The motor has a main body. At least one spoke structure is coupled to and extends generally radially from a periphery of the main body so as to be exposed to airflow caused by rotation of the fan. An electronic component of the motor is operatively associated with the spoke structure such that heat of the electronic component is conducted to the spoke structure.
In accordance with another aspect of the invention, a method of providing an electric motor provides a motor for driving a fan. The motor has a main body and spoke structure coupled to and extending generally radially from a periphery of the main body so as to be exposed to airflow caused by rotation of the fan. An electronic component of the motor is located to be operatively associated with the spoke structure such that heat of the electronic component is conducted to the spoke structure.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.